Question about bf904 SPICE model
I have a question about this SPICE model: http://www.nxp.com/documents/spice_m...pice_BF904.prm
for this mosfet: http://www.nxp.com/products/rf/trans....html#overview
I see that there are 4 mosfet models and mosfet devices there. Does it mean that there are two diferent models for this transistor and I have to choose one of them or otherwise this means that transistor's model is build by 4 mosfets?
Ty very much, any advice would be helpful.
You need two MOSFETs to model a dual-gate MOSFET. For the other two transistors, take at look at the BF904 datasheet, particularly the symbol.
I don't really get it, sorry. I mean, I understand that I need 2 mosfet to model a 2gate mosfet but I don't understand what do you mean. Do I have to choose a couple of mosfets? Because in the spice model it seems that the 4 mosfets are connected between them.
My first guess was that there are 2 mosfets for one of the packages and 2 for the other one but I don't know how to choose what pair I need. Am I right or do I have to use the whole model?
Ty for your quick answer.
You still not looked thoroughly at the symbol schematic.
Please count the red circcles, I see 4 gates respectively four single gate transistors. You can sketch the simulation circuit and realize that it implements the same topology plus some package parasitics.
Oh, Ty very much. You have been very helpful.